Sound record



puma STATES ATENT FFIcE SOUND RECORD George Schneider, Montolair, N. J., assignor to Gelanese Corporation of America, a corpora tion of Delaware No Drawing. Application November 7, 1930 Serial No. 494,205

3 Claims. (01. 154-43) This invention relates to records for reproductriphenyl phosphate, dibutyl tartrate, diethyl ing and/or recording sound and relates more tartrate, dibutyl phthalate, etc., the choice departicularly to such sound records wherein the pending on the particular cellulose derivative sound track is contained in a surface made of a present. As to the proportions of plasticizer to 5 plastic composition containing a derivative of the derivative of cellulose employed, generally I 0 cellulose. have found that amounts varying from to An object of my invention is to prepare soimd say 40%, of the weight of the derivative of cellurecords from which tones of pure quality may be lose present, produce excellent results. If the reproduced and which are relatively inexpensive. record is to be employed for recording sound, a

19 A further object of my invention is to prepare larger amount of plasticizer is employed to imsound records having a sound reproducing surpart the desired degree of softness.

face made of a plastic composition containing a The cellulosic plastic material preferably conderivative of cellulose while the core thereof is tains no hard filling materials, but the use of made of a cheap composition. Other objects of such hard filling materials is not excluded.

15 this invention will appear from the following de- While I prefer to employ little or no filling mate- 7 tailed description. rial at all, if it is desired to reduce the cost of the It has been proposed to make sound records product, a soft or lubricating filler such as talc, made of plastic compositions containing derivanot to exceed 25% of the weight of the cellulosic tives of cellulose. Since such cellulosic plastics plastic material, may be employed. The pig- 0 are relatively expensive, it would be desirable to meat employed should preferably be in finely di- 7 replace part thereof with a cheaper material, vided form. To impart color, a suitable dye such since from the point of view of sound reproducas nigrosine may be added. tion, it is not necessary that the interior of the The cellulosic plastic material may be made in record he of such cellulosic plastic material. any desired manner. I prefer to make a plastic 25 I found that a composition containing mass by gelatinizing the derivative of cellulose resin and a plasticizer or softening agent for the and a plasticizer and any other desired inrosin is it excellent and cheap material that gredients with a volatile solvent such as acetone, be employed as a core upon which sheets of alcohol and/or benzene, working the mass on collulosic material may be laminated. The sheets heated malaxating rolls to remove excess solvent,

30 ofcelloiosic plastics easily adhere to the rosin and then forming sheets from the mass. Or

composition to form a firm bond. films may be cast from solutions of the derivative In accordance with my invention, I prepare of cellulose or plasticizer in a volatile solvent sound records, the sound reproducing surface of upon a smooth surface. The sheets or films so which is formed of a layer or sheet composed of formed may be out into discs corresponding to plastic composition containing a derivative of the size of the record desired, and these discs cellulose and a suitable plasticizer supported on may be used for laminating with the cores conor laminated with a core made of a composition taining the rosin and plasticizer.

containing rosin and a plasticizer or softening If desired the plastic compositon containing agent for the rosin. an organic derivative of cellulose may be made in For the reproducing surface, a plastic comthe form of powder by finely dividing the plastic position containing a suitable derivative of cellumaterial by gelatinization of the ingredients by lose such cellulose nitrate or an organic deriva solvent and removing the solvent, or such powti of cellulose may be employed. Such order may be formed by finely grinding the dried garlic derivative of cellulose may be organic esters organic derivative of cellulose and the plasticizer 45 of cellulose and cellulose ethers. Examples of with or Without other ingredients. These pow- 10 organic esters of cellulose are cellulose acetate, ders may be molded under heat and pressure cellulose formate, cellulose propionate and celluaround the core piece containing the rosin belose hutyrate, while examples of cellulose ethers tween the sound matrices to produce the sound are ethyl cellulose, methyl cellulose and benzyl record. Alternatively, a coating composition 59 11 1 containing the derivative of cellulose and the 05 The cellulose derivative contained in the replasticizer and a volatile solvent may be coated producing surface is plasticized with a plasticizer ED the Core Containing the suitable softening agent, examples of which are As stated, in order to reduce the cost of manucamphor, Xylene monomethyl sulfonamid, difacture, the interiors or cores of the sound ethyl phthalate, dimethyl phthalate, triaoetin, records are made of a composition containing a rosin and a plasticizer or softening agent for the rosin. The plasticizer or softening agent is preferably the same one as that employed in the cellulosic plastic composition but it may be other materials such as acetanilid. Further to reduce the cost of the core material, filling materials such as carbon black,iron oxide, silica, barytes, china clay, talc, cotton flock, etc. may be incorporated. If desired shellac or other resins or gums may also be added as may also be dyes like nigrosine.

If a single record is to be made, one film or sheet of cellulosic plastic is applied to one side of the core containing the rosin; if a double record is to be made a sheet or film is applied to each side of the core.

In making the core material, the following procedure may be employed. The rosin is melted with the plasticizer and filling materials are added by means of malaxating rolls and the like. Such material is then cut into blanks, heated on a steam table and assembled with the blanks of the cellulosic plastic material. The assembly is then pressed under elevated pressures and at elevated temperatures between matrices having the sound record therein. The sheets or films of cellulosic material adhere firmly to the core of the plasticized rosin.

By this invention sound records, which may be employed for reproducing and/or recording and which reproduce sounds of pure tone, may be made inexpensively. Furthermore the film or sheet of cellulosic plastic adheres firmly to the core of the plasticized rosin.

In order further to illustrate my invention, but without being limited thereto, the following specific example is given.

Example 850 parts of G H rosin are melted and to this are added Parts by weight Acetanilid 150 Nigrosine 12.5

The acetanilid may be replaced in whole or in part with the plasticizer employed in making the cellulosic plastic.

After the ingredients have dissolved to form a homogeneous mass, there are thoroughly incor porated therein Parts by Weight Lamp black 30 Iron oxide 7% The lamp black and iron oxide are in finely pulverized form. The mass is then poured onto limed concrete to cool, whereupon it solidifies into a glossy black solid. This is then broken up into small pieces and is then worked upon heated malaxating rolls during which time inert filling materials, such as a mixture of iron oxide, lamp black, barytes, china clay and cotton flock, in any desired amount may be added. During this time, if desired, shellac in amounts up to the amount of rosin present, may be added to the mass on the rolls.

The sheets formed on the rolls are cut into discs having a diameter of the finished record. Thereupon discs of cellulosic plastics are superposed upon the discs containing the rosin material. The cellulosic plastics may be of the following com position:

Parts by weight (A) Cellulose nitrate 100 Oamphor 40 Parts by weight (B) Cellulose acetate 100 Diethyl phthalate 40 The assembly of the rosin composition core and the sheets or films of the cellulosic plastic is heated on steamed tables and pressed between sound matrices to produce the finished sound rec- 0rd.

It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing from the spirit of my invention.

Having described my invention, what I desire to secure by Letters Patent is:

1. A sound record having a reproducing surface contained in an outer layer made of a plastic composition having a basis of a derivative of cellulose, said record having an interior made of a composition having a basis of rosin, and containing the same plasticizer as is contained in the outer layer.

2. A sound record having a reproducing surface contained in an outer layer made of a plastic composition having a basis of cellulose acetate, said record having an interior made of a composition having a basis of rosin, and containing the same plasticizer as is contained in the outer layer.

3. A sound record having a reproducing surface contained in an outer layer made of a plastic com position having a basis of cellulose nitrate, said record having an interior made of a composition having a basis of rosin, and containing the same plasticizer as is contained in the outer layer.

GEORGE SCHNEIDER. 

